1. Field of the Invention
The present invention relates to a developing device and a process cartridge for use in an electrophotographic image-forming system.
2. Description of the Related Art
Known is a process cartridge system in which an electrophotographic photoreceptor and a developing device are integrated in a cartridge, and the cartridge is demountable from a main body of an electrophotographic image forming apparatus. With this process cartridge system, an operator can maintain the apparatus without depending on a service engineer. Thus, this process cartridge system has been widely employed in image forming apparatuses.
The above-mentioned process cartridge system includes a developing device for developing a latent image formed on an electrophotographic photoreceptor with a developer. Such a developing device has a stationary magnet disposed in a cylindrical developing roller. By rotating the developing roller, the developer is fed to a photosensitive drum (the photoreceptor).
The support mechanism of the developing roller will be described with reference to FIGS. 11 and 12. The electrophotographic photoreceptor (not shown) is rotatably supported by the frame of the cartridge. As shown in FIG. 11, a developing roller 10d has gap-holding members 10m rotatably disposed at both ends thereof, for maintaining a predetermined gap between the electrophotographic photoreceptor and the developing roller 10d. 
The developing roller 10d has developing-roller flanges 10d1 disposed at both ends thereof. Each developing-roller flange 10d1 is held by a bearing member 10w. 
Also, the developing roller 10d has a stationary magnet 10c disposed inside thereof. The stationary magnet 10c is held by stationary-magnet holding members 10c1.
The bearing members 10w and the stationary-magnet holding members 10c1 are positioned by corresponding positioning members 10f5 disposed in a toner-developing frame 10f1. With this structure, a relative position between the developing roller 10d and the stationary magnet 10c is determined.